D2D Communication Resource Allocation Mode Switching
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Solution Overview
Problem
Current solutions for establishing a radio resource control (RRC) connection in LTE networks are not directly applicable to device-to-device (D2D) communications, as they rely on the presence of cellular radio bearers, which are not established in D2D idle mode, and do not efficiently manage resource allocation for D2D transmissions within the network.
Innovation Solution
The proposed solution involves determining the appropriate resource allocation mode (D2D resource allocation mode 1 or 2) based on system information and network conditions, allowing the UE to transition from RRC idle to connected mode specifically for D2D communications, using existing D2D radio bearers, and coordinating with the network to avoid interference with cellular transmissions through dynamic resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current RRC connection establishment solutions are used for D2D communications, then cellular network coverage and control are maintained, but resource allocation efficiency deteriorates and power consumption increases due to unnecessary cellular infrastructure reliance
Solution Approach 1:
The patent segments the communication resource allocation into two distinct modes: Mode 1 where the eNB schedules D2D resources, and Mode 2 where the UE autonomously selects resources from a pre-configured pool. This segmentation allows the system to choose the most efficient allocation method based on network conditions, improving overall resource allocation efficiency while reducing unnecessary power consumption by enabling autonomous operation when appropriate.
Solution Approach 2:
The patent implements dynamic resource allocation mode selection where the UE can switch between Mode 1 (network-controlled) and Mode 2 (autonomous) based on system information blocks (SIBs) and network conditions. This dynamic approach allows the system to optimize resource allocation efficiency in real-time and reduce power consumption by selecting autonomous mode when network control is not required, rather than always relying on cellular infrastructure.
2Ease of operation
If D2D communications use existing cellular radio bearers, then network control and coordination are maintained, but device complexity increases and operation becomes less efficient
Solution Approach 1:
The patent extracts the D2D communication functionality from the traditional cellular radio bearer framework. Instead of requiring full cellular radio bearer establishment for D2D communications, the system uses a simplified D2D radio bearer that can operate independently in autonomous mode. This extraction reduces device complexity by eliminating unnecessary cellular protocol stack operations while maintaining ease of operation through dedicated D2D resource pools and simplified scheduling mechanisms.
Solution Approach 2:
The patent enables D2D UEs to self-configure and self-manage their own radio bearers for D2D communications in autonomous mode. The UE can independently select resources from pre-configured pools, establish D2D radio bearers without full cellular network involvement, and manage their own transmissions. This self-service capability significantly reduces device complexity by eliminating dependence on complex cellular radio bearer management while maintaining ease of operation through autonomous resource selection.
3Object-affected harmful factors
If D2D transmissions are scheduled by the eNB, then network coordination and interference management are improved, but resource allocation overhead and network load increase
Solution Approach 1:
The patent implements partial network control where the eNB provides partial coordination through pre-configuring resource pools via system information blocks (SIBs) and maintaining the ability to schedule Mode 1 transmissions. For Mode 2 autonomous operation, the eNB provides just enough control (resource pool configuration) to prevent severe interference, while allowing UEs to independently manage their transmissions. This partial action approach maintains adequate interference management while significantly reducing resource allocation overhead and network load compared to full eNB scheduling.
Data Source
AI summary
Technology for performing device-to-device (D2D) communications is disclosed. A user equipment (UE) can identify D2D data to be transmitted from the UE. The D2D data can be identified when the UE is in a radio resource control (RRC) idle. The UE can be limited to using a defined resource allocation mode to transmit the D2D data from the UE. A service request procedure can be initiated at the UE. The service request procedure can trigger the UE to perform an RRC connection establishment procedure with an evolved node B (eNB) to switch the UE from the RRC idle mode to an RRC connected mode. The UE can receive an uplink (UL) grant from the eNB for communicating the D2D data from the UE. The UE can send the D2D data using the UL grant provided by the eNB.